Transforming growth factor-β1 polymorphisms and chronic obstructive pulmonary disease: a meta-analysis

Abstract

Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease in which gene- environment interactions play a critical role in disease onset and progression. Transforming growth factor-β 1 (TGF-β 1) is one of several candidate loci for the pathogenesis of COPD, and is highly polymorphic. To derive a more precise estimation of the relationship between the T869C and C-509T polymorphisms of the TGF-β 1 gene and COPD, a meta-analysis of 11 published case-control studies was performed. Ten studies with 1507 cases and 2542 controls for T869C polymorphism and six studies with 955 cases and 2136 controls for C-509T polymorphism were included. The pooled odds ratios were performed respectively for allele contrasts, additive genetic model, dominant genetic model and recessive genetic model. A subgroup analysis was also performed by ethnicity for T869C polymorphism. With respect to T869C polymorphism, a significant association of TGF-β 1 gene polymorphism at 869T/C with COPD was observed in the overall analysis (C vs. T: OR 0.82, 95%CI 0.70-0.96, P = 0.01). In the subgroup analysis by ethnicity, significant risks were also found in the Caucasian population for C vs. T (OR 0.77, 95%CI 0.60-0.98, P = 0.03), but not in the Asian population (C vs. T: OR 0.88, 95%CI 0.76-1.03, P = 0.10). With respect to C-509T polymorphism, no significant association with COPD was demonstrated in the overall analysis (T vs. C: OR 0.84, 95%CI 0.68- 1.04, P = 0.11). Potentially functional TGF-β 1 T869C polymorphism may play a low penetrance role in COPD susceptibility in an ethnicity-specific manner.